/*
 * Copyright (c) 1997, 2013, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 *
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 */
package javax.swing;

import java.beans.ConstructorProperties;

import java.awt.*;
import java.awt.event.*;
import java.awt.image.*;

import javax.swing.plaf.*;
import javax.swing.event.*;
import javax.accessibility.*;

import java.io.ObjectOutputStream;
import java.io.ObjectInputStream;
import java.io.IOException;


/**
 * An implementation of a "push" button. <p> Buttons can be configured, and to some degree
 * controlled, by <code><a href="Action.html">Action</a></code>s.  Using an <code>Action</code> with
 * a button has many benefits beyond directly configuring a button.  Refer to <a
 * href="Action.html#buttonActions"> Swing Components Supporting <code>Action</code></a> for more
 * details, and you can find more information in <a href="https://docs.oracle.com/javase/tutorial/uiswing/misc/action.html">How
 * to Use Actions</a>, a section in <em>The Java Tutorial</em>. <p> See <a
 * href="https://docs.oracle.com/javase/tutorial/uiswing/components/button.html">How to Use Buttons,
 * Check Boxes, and Radio Buttons</a> in <em>The Java Tutorial</em> for information and examples of
 * using buttons. <p> <strong>Warning:</strong> Swing is not thread safe. For more information see
 * <a href="package-summary.html#threading">Swing's Threading Policy</a>. <p>
 * <strong>Warning:</strong> Serialized objects of this class will not be compatible with future
 * Swing releases. The current serialization support is appropriate for short term storage or RMI
 * between applications running the same version of Swing.  As of 1.4, support for long term storage
 * of all JavaBeans&trade; has been added to the <code>java.beans</code> package. Please see {@link
 * java.beans.XMLEncoder}.
 *
 * @author Jeff Dinkins
 * @beaninfo attribute: isContainer false description: An implementation of a \"push\" button.
 */
@SuppressWarnings("serial")
public class JButton extends AbstractButton implements Accessible {

  /**
   * @see #getUIClassID
   * @see #readObject
   */
  private static final String uiClassID = "ButtonUI";

  /**
   * Creates a button with no set text or icon.
   */
  public JButton() {
    this(null, null);
  }

  /**
   * Creates a button with an icon.
   *
   * @param icon the Icon image to display on the button
   */
  public JButton(Icon icon) {
    this(null, icon);
  }

  /**
   * Creates a button with text.
   *
   * @param text the text of the button
   */
  @ConstructorProperties({"text"})
  public JButton(String text) {
    this(text, null);
  }

  /**
   * Creates a button where properties are taken from the
   * <code>Action</code> supplied.
   *
   * @param a the <code>Action</code> used to specify the new button
   * @since 1.3
   */
  public JButton(Action a) {
    this();
    setAction(a);
  }

  /**
   * Creates a button with initial text and an icon.
   *
   * @param text the text of the button
   * @param icon the Icon image to display on the button
   */
  public JButton(String text, Icon icon) {
    // Create the model
    setModel(new DefaultButtonModel());

    // initialize
    init(text, icon);
  }

  /**
   * Resets the UI property to a value from the current look and
   * feel.
   *
   * @see JComponent#updateUI
   */
  public void updateUI() {
    setUI((ButtonUI) UIManager.getUI(this));
  }


  /**
   * Returns a string that specifies the name of the L&amp;F class
   * that renders this component.
   *
   * @return the string "ButtonUI"
   * @beaninfo expert: true description: A string that specifies the name of the L&amp;F class.
   * @see JComponent#getUIClassID
   * @see UIDefaults#getUI
   */
  public String getUIClassID() {
    return uiClassID;
  }


  /**
   * Gets the value of the <code>defaultButton</code> property,
   * which if <code>true</code> means that this button is the current
   * default button for its <code>JRootPane</code>.
   * Most look and feels render the default button
   * differently, and may potentially provide bindings
   * to access the default button.
   *
   * @return the value of the <code>defaultButton</code> property
   * @beaninfo description: Whether or not this button is the default button
   * @see JRootPane#setDefaultButton
   * @see #isDefaultCapable
   */
  public boolean isDefaultButton() {
    JRootPane root = SwingUtilities.getRootPane(this);
    if (root != null) {
      return root.getDefaultButton() == this;
    }
    return false;
  }

  /**
   * Gets the value of the <code>defaultCapable</code> property.
   *
   * @return the value of the <code>defaultCapable</code> property
   * @see #setDefaultCapable
   * @see #isDefaultButton
   * @see JRootPane#setDefaultButton
   */
  public boolean isDefaultCapable() {
    return defaultCapable;
  }

  /**
   * Sets the <code>defaultCapable</code> property,
   * which determines whether this button can be
   * made the default button for its root pane.
   * The default value of the <code>defaultCapable</code>
   * property is <code>true</code> unless otherwise
   * specified by the look and feel.
   *
   * @param defaultCapable <code>true</code> if this button will be capable of being the default
   * button on the <code>RootPane</code>; otherwise <code>false</code>
   * @beaninfo bound: true attribute: visualUpdate true description: Whether or not this button can
   * be the default button
   * @see #isDefaultCapable
   */
  public void setDefaultCapable(boolean defaultCapable) {
    boolean oldDefaultCapable = this.defaultCapable;
    this.defaultCapable = defaultCapable;
    firePropertyChange("defaultCapable", oldDefaultCapable, defaultCapable);
  }

  /**
   * Overrides <code>JComponent.removeNotify</code> to check if
   * this button is currently set as the default button on the
   * <code>RootPane</code>, and if so, sets the <code>RootPane</code>'s
   * default button to <code>null</code> to ensure the
   * <code>RootPane</code> doesn't hold onto an invalid button reference.
   */
  public void removeNotify() {
    JRootPane root = SwingUtilities.getRootPane(this);
    if (root != null && root.getDefaultButton() == this) {
      root.setDefaultButton(null);
    }
    super.removeNotify();
  }

  /**
   * See readObject() and writeObject() in JComponent for more
   * information about serialization in Swing.
   */
  private void writeObject(ObjectOutputStream s) throws IOException {
    s.defaultWriteObject();
    if (getUIClassID().equals(uiClassID)) {
      byte count = JComponent.getWriteObjCounter(this);
      JComponent.setWriteObjCounter(this, --count);
      if (count == 0 && ui != null) {
        ui.installUI(this);
      }
    }
  }


  /**
   * Returns a string representation of this <code>JButton</code>.
   * This method is intended to be used only for debugging purposes, and the
   * content and format of the returned string may vary between
   * implementations. The returned string may be empty but may not
   * be <code>null</code>.
   *
   * @return a string representation of this <code>JButton</code>
   */
  protected String paramString() {
    String defaultCapableString = (defaultCapable ? "true" : "false");

    return super.paramString() +
        ",defaultCapable=" + defaultCapableString;
  }

/////////////////
// Accessibility support
////////////////

  /**
   * Gets the <code>AccessibleContext</code> associated with this
   * <code>JButton</code>. For <code>JButton</code>s,
   * the <code>AccessibleContext</code> takes the form of an
   * <code>AccessibleJButton</code>.
   * A new <code>AccessibleJButton</code> instance is created if necessary.
   *
   * @return an <code>AccessibleJButton</code> that serves as the <code>AccessibleContext</code> of
   * this <code>JButton</code>
   * @beaninfo expert: true description: The AccessibleContext associated with this Button.
   */
  public AccessibleContext getAccessibleContext() {
    if (accessibleContext == null) {
      accessibleContext = new AccessibleJButton();
    }
    return accessibleContext;
  }

  /**
   * This class implements accessibility support for the
   * <code>JButton</code> class.  It provides an implementation of the
   * Java Accessibility API appropriate to button user-interface
   * elements.
   * <p>
   * <strong>Warning:</strong>
   * Serialized objects of this class will not be compatible with
   * future Swing releases. The current serialization support is
   * appropriate for short term storage or RMI between applications running
   * the same version of Swing.  As of 1.4, support for long term storage
   * of all JavaBeans&trade;
   * has been added to the <code>java.beans</code> package.
   * Please see {@link java.beans.XMLEncoder}.
   */
  @SuppressWarnings("serial")
  protected class AccessibleJButton extends AccessibleAbstractButton {

    /**
     * Get the role of this object.
     *
     * @return an instance of AccessibleRole describing the role of the object
     * @see AccessibleRole
     */
    public AccessibleRole getAccessibleRole() {
      return AccessibleRole.PUSH_BUTTON;
    }
  } // inner class AccessibleJButton
}
